Proton Sponge

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Origins

Proton Sponge is a compound that was first made in 1968 by Roger Alder FDS. He made it at the University of Bristol. The actual name for it is 1,8-Bis(dimethylamino)napthalene, however the name Proton Sponge was given to it by Sigma-Aldrich. The IUPAC name is N,N,N',N'-tetramethylnaphthalene-1,8-diamine. Another name it can go by is (DMAN).

Preparation

You may buy this commercially, however you may also prepare it through the methylation of 1,8-diaminonapthalene with iodomethane or dimethyl sulfate.

Essential Properties

It has a pKa of 12.1, making it one of the strongest amine bases known. It is highly basic because of the relief of strain upon protonation and/or the strong interaction between the nitrogen pairs. It is a weak nucleophile, which is one reason it is used in organic synthesis as a non-nucleophilic base. It absorbs the protons slowly, hence the sponge name. The molecular formula is C14H18N2. The molar mass is 214.31g/mol. The melting point is 47.8°C. The boiling point is between 144 and 145°C. It is insoluble in water. It is found to be light sensitive. It is a pale brownish-pink crystalline powder.

% Compositions

By Number
C = 41.18%
H = 52.94%
N = 5.82%

By Mass
C = 78.46%
H = 8.47%
N = 13.07%

Uses

Proton Sponge is used to absorb protons slowly, hence the name Proton Sponge. This is important in many reactions to view them in a sort of slower manner. When it absorbs the protons its structure changes. It then consists of a rigid aromatic framework, substituted by two amino groups that are connected by a powerful hydrogen bond bridge.(See below Picture)


external image moz-screenshot-1.png0.gif
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THS-46DM0KJ-1H&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1100991292&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=95f326bd11a9ec1b91f0ef7876e54efb


Citations/Other recommended sites

Authors, Various. "1,8-Bis(dimethylamino)naphthalene". Chemicalbook.com. 11/16/09 <http://www.chemicalbook.com/ProductChemicalPropertiesCB4163778_EN.htm>.

"Proton Sponge Picture". Wikipedia. 11/18/09 <http://upload.wikimedia.org/wikipedia/commons/thumb/0/06/Proton_sponge.svg/200px-Proton_sponge.svg.png>.

Authors, Various. "1,8-Bis(dimethylamino)naphthalene". Wikipedia. 11/18/09 <http://en.wikipedia.org/wiki/1,8-Bis%28dimethylamino%29naphthalene>.

Korzhenevska, Nadiya. "Tetrahedron Titles". Science Direct. 11/19/09 <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THS-46DM0KJ-1H&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1100991292&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=95f326bd11a9ec1b91f0ef7876e54efb>.